Long-term Impacts of Brace Treatment for Adolescent Idiopathic Scoliosis on Body Composition, Paraspinal Muscle Morphology, and Bone Mineral Density

The effect of brace treatment history on bone density in preoperative patients with adolescent idiopathic scoliosis (AIS) assessed by vertebral bone quality (VBQ) score: a retrospective propensity score-matched analysis

INTRODUCTION

Adolescent idiopathic scoliosis (AIS), a prevalent condition among teenagers, is often accompanied by osteopenia. However, the impact of brace treatment on bone density in AIS patients remains a matter of debate. The Vertebral bone quality (VBQ) score, derived from MRI signal intensity, has been shown to correlate with bone mineral density (BMD). Yet, no studies to date have drawn comparisons between VBQ scores in preoperative AIS patients who had brace treatment history and those who have not received brace treatment.

OBJECTIVE

This study aims to elucidate the influence of brace treatment on bone density in AIS patients using VBQ score.

METHODS

A retrospective analysis was conducted on 243 AIS patients, each with Cobb angles ranging from 50-70°, who had undergone preoperative MRI scans. The patients were segregated into two cohorts: those who received brace treatment (n = 174) and those who did not (n = 69). Through propensity score matching, a total of 53 matched pairs were selected for further analysis. VBQ scores were extracted from T1-weighted MRI scans.

RESULTS

Post-matching, no significant baseline discrepancies were observed between the two groups. Interestingly, brace-treated patients exhibited lower average VBQ scores than their non-brace-treated counterparts (2.43 ± 0.11 vs. 2.55 ± 0.12, p < 0.01), suggesting a higher bone density. Furthermore, a negative correlation was observed between VBQ scores and the duration of brace usage (R2 = 0.3853, p < 0.01).

CONCLUSION

Brace treatment may potentially enhance bone density in AIS patients by mitigating vertebral fat infiltration. The utilization of VBQ scores presents an alternative, potentially robust approach to assessing bone quality.

Comparison of elasticity changes in the paraspinal muscles of adolescent patients with scoliosis treated with surgery and bracing

Scoliosis is a three-dimensional spinal deformity, and paraspinal muscles play an important role as stabilizers of the spinal curve. In this prospective study, we compared elasticity changes in the paraspinal muscles of adolescent patients with scoliosis after surgery or bracing. Elasticity was measured on the concave and convex sides of the paraspinal muscles at the apex of the curve at the beginning of treatment and 6 and 12 months after treatment. Twenty-six patients with correction surgery (n = 15) or bracing (n = 11) were included. At initial evaluation, the Cobb angle was larger in the surgery group (72.3 ± 20.2° in surgery vs. 30.6 ± 5.1° in brace, p < 0.001). The estimated mean elasticity value of the paraspinal muscles was lower in the surgery group at baseline on the convex side (15.8 vs. 22.8 kPa, p = 0.037) and 6 months on both the concave (12.1 vs. 22.7 kPa, p = 0.004) and convex (13.4 vs. 23.8 kPa, p = 0.005) sides. There was a significant stiffness decrease from baseline to 6 months on the concave side in the surgery group (5.9 kPa, p = 0.025). However, the elasticity change recovered at 12 months without significant differences between the two groups.

Associations Between Physical Activity and Adolescent Idiopathic Scoliosis: A Systematic Review and Meta-analysis

OBJECTIVE

To investigate the associations between adolescent idiopathic scoliosis (AIS) and physical activity (PA).

DATA SOURCES

MEDLINE, EMBASE, AMED, SPORTDiscus, Cochrane Library, and CINAHL electronic databases were searched from inception to August 2022/plus citation tracking.

STUDY SELECTION

Observational studies of participants with radiographically confirmed AIS with ≥10° lateral spinal curvature (Cobb method) and comparator groups without AIS that measured PA were selected by 2 reviewers.

DATA EXTRACTION

Data were extracted independently and cross-checked by 2 reviewers. Risk of bias was evaluated using Newcastle Ottawa Scales and overall confidence in the evidence using the GRADE approach.

DATA SYNTHESIS

Sixteen studies with 9627 participants (9162, 95% women) were included. A history of vigorous PA significantly reduced the odds of being newly diagnosed with AIS by 24% (odds ratio [OR] 0.76, 95% confidence interval [CI] 0.65-0.89) (high certainty). Moderate PA reduced odds by 13% (moderate certainty) and light PA increased odds by 9% (low certainty), but neither analysis was statistically significant. Ballet or gymnastics (OR 1.47, 95% CI 3.08 (1.90, 5.00) were the only individual sports significantly associated with AIS diagnosis (moderate certainty). Case-control studies of people with and without AIS provided greater evidence that having AIS reduces vigorous PA and sports participation, and less evidence light PA and walking are affected.

CONCLUSION

Adolescents who participate in more vigorous PA are less likely to be diagnosed with AIS. Ballet and gymnastics are associated with AIS diagnosis, but the direction of this association is uncertain. People with AIS are likely to do less vigorous physical and sporting activity compared with those without AIS, which could negatively affect health and quality of life. Further research is warranted into the inter-relations between PA and AIS, studies need to be of sufficient size, include men, and evaluate vigorous including higher-impact PA compared with moderate or light PA.

Long-Term Influence of Paraspinal Muscle Quantity in Adolescent Idiopathic Scoliosis Following Deformity Correction by Posterior Approach

Pedicle screw instrumentation (PSI) through posterior approach has been the mainstay of deformity correction for adolescent idiopathic scoliosis (AIS). However, changes in the quantity of paraspinal muscles after AIS surgery has remained largely unknown. The aim of this study was to investigate long-term follow-up changes in paraspinal muscle volume in AIS surgery via a posterior approach. Forty-two AIS patients who underwent deformity correction by posterior approach were analyzed through a longitudinal assessment of a cross-sectional area (CSA) in paraspinal muscles with a minimum five-year follow-up. The CSA were measured using axial computed tomography images at the level of the upper endplate L4 by manual tracing. The last follow-up CSA ratio of the psoas major muscle (124.5%) was significantly increased compared to the preoperative CSA ratio (122.0%) (p < 0.005). The last follow-up CSA ratio of the multifidus and erector spine muscles significantly decreased compared to the preoperative CSA ratio (all p < 0.005). The CSA ratio of the erector spine muscle was correlated with the CSA ratio of the psoas major (correlation coefficient = 0.546, p < 0.001). Therefore, minimizing the injury to the erector spine muscle is imperative to maintaining psoas major muscle development in AIS surgery by posterior approach.